Noise

About: Noise is a research topic. Over the lifetime, 5111 publications have been published within this topic receiving 69407 citations. The topic is also known as: Мопсы танцуют под радио бандитов из сталкера 10 часов.

Behavioral Responses by Two Songbirds to Natural-Gas-Well Compressor Noise

Abstract: Several urban-adapted species sing at a higher frequency in noisy urban areas than in quiet locations. Yet it remains unclear whether the ability to adjust signals in response to noise is related to an ability to persist in noisy areas, because signal change and habitat use are infrequently measured within a single study. We investigated occupancy and signal change in response to noise in the Blue-gray Gnatcatcher (Polioptila caerulea) and the Spotted Towhee (Pipilo maculatus) using a study system that eliminates uncontrolled effects of habitat features that may influence song frequency or habitat use and controls for the negative effect of noise on bird surveys. We predicted that species that alter the frequency of their vocalizations in response to noise would use noisy and quiet areas similarly, and that species that do not adjust their vocalizations in response to noise may avoid noisy areas. Both study species were uninfluenced by noise in their habitat occupancy, but only Spotted Towhees sa...

Quiet Time: A Noise Reduction Initiative in a Neurosurgical Intensive Care Unit

Abstract: Background High noise levels in intensive care units are common. Increased noise levels can lead to sleep deprivation, increased pain perception, and delirium. The most common cause of reducible noise in intensive care units often is attributed to staff conversations. Objectives In January 2015, the neurosurgical intensive care unit staff identified noise as a problem, referencing complaints from other disciplines and family members. Quiet times from 3 am to 5 am and from 3 pm to 5 pm were agreed upon. An improvement plan was developed with a goal to decrease noise levels by 10 decibels in 6 months. Methods Using a decibel meter, noise data were collected in 4 locations every 30 minutes during the chosen times for 8 days. Quiet time was implemented 1 week after staff, patient, and family education was completed. Decibel data were collected and evaluated after 60 days. Results There were statistically significant reductions in noise levels at nurses' station left (P = .04) and the bed 9 entrance (P = .02). Noise levels were lower, but not significantly so, for nurses' station right (P = .12) and the bed 4 entrance (P = .06). Noise levels during quiet time decreased to an average of 10 to 15 decibels lower than baseline data. Conclusions Sharing baseline data was effective to heighten noise awareness. During quiet time, limiting conversations, eliminating environmental noise, and dimming the lights as a reminder to be quiet are 3 simple strategies that can be implemented to lessen noise.

Separation of musical sources and structure from single-channel polyphonic recordings

Abstract: The thesis deals principally with the separation of pitched sources from singlechannel polyphonic musical recordings. The aim is to extract from a mixture a set of pitched instruments or sources, where each source contains a set of similarly sounding events or notes, and each note is seen as comprising partial, transient and noise content. The work also has implications for separating nonpitched or percussive sounds from recordings, and in general, for unsupervised clustering of a list of detected audio events in a recording into a meaningful set of source classes. The alignment of a symbolic score/MIDI representation with the recording constitutes a pre-processing stage. The three main areas of contribution are: firstly, the design of harmonic tracking algorithms and spectralfiltering techniques for removing harmonics from the mixture, where particular attention has been paid to the case of harmonics which are overlapping in frequency. Secondly, some studies will be presented for separating transient attacks from recordings, both when they are distinguishable from and when they are overlapping in time with other transients. This section also includes a method which proposes that the behaviours of the harmonic and noise components of a note are partially correlated. This is used to share the noise component of a mixture of pitched notes between the interfering sources. Thirdly, unsupervised clustering has been applied to the task of grouping a set of separated notes from the recording into sources, where notes belonging to the same source ideally have similar features or attributes. Issues relating to feature computation, feature selection, dimensionality and dependence on a symbolic music representation are explored. Applications of this work exist in audio spatialisation, audio restoration, music content description, effects processing and elsewhere.

A new noise reduction method using linear prediction error filter and adaptive digital filter

Abstract: A technique that uses a linear prediction error filter (LPEF) and an adaptive digital filter (ADF) to achieve noise reduction in a speech degraded by additive background noise is proposed. Since a speech signal can be represented as the stationary signal over a short interval of time, most of speech signal can be predicted by the LPEF. On the other hand, when the input signal of the LPEF is a background noise, the prediction error signal becomes white. Assuming that the background noise is generated by exciting a linear system with a white noise, then we can reconstruct the background noise from the prediction error signal by estimating the transfer function of noise generation system. This estimation is performed by the ADF which is used as system identification. Noise reduction is achieved by subtracting the reconstructed noise from the speech degraded by additive background noise.

Cardiovascular effects of impulse noise, road traffic noise, and intermittent pink noise at LAeq = 75 dB, as a function of sex, age, and level of anxiety: a comparative study. II. Digital pulse level and blood pressure data.

Abstract: In a previous paper, in which the experimental conditions of the present research are fully described (Parrot et al., this issue), heart rate (HR) was studied in 60 male and in 60 female subjects in response to a pile-driver noise (P), a gunfire noise (G), a road traffic noise (T), and an intermittent pink noise (R), all noises being emitted at the same LAeq = 75 dB for 15 min. Digital pulse level (PL) responses were concomitantly surveyed by the use of pulse oximetry, allowing continuous arterial oxygen saturation (SaO2) readings. An index of pulse reactivity (PRI) could be calculated. Arterial blood pressure was measured 7 times from the beginning to the end of each trial. At rest, within the last minutes preceding each exposure to any of the 4 noises, no difference for conditions or for age in prestimulus PL was observed. In all cases, sex is a highly significant source of variation: Mean resting SaO2 values are higher in women than in men. Mean SaO2 at rest was also found to be significantly higher in anxious (Am) than in anxiety-free (Nm) men. When the noise was on for 15 min, increase in PL prevailed to be in most cases in men. In contrast, decrease or near-zero changes prevailed in 1 case out of 2 in the female subgroups. In all groups, the mean PRIs are significantly higher in men. In no case did the age factor prove to be a significant source of PRI variation.(ABSTRACT TRUNCATED AT 250 WORDS)